Module Error with pyang sample-xml-skeleton and IOS-XE YANG models

[DrSchw0b]

Hi,

I am new to YANG/Netconf. Apologies in advance if there is an obvious answer to my question.

I am using the Yang models of the https://github.com/YangModels/yang repositories, Python 3.9.2 and pyang 2.5.3 for the following:

I am trying to get a feeling for the YANG models in combination with Netconf. I came across pyang with the “sample-xml-skeleton” format. As a beginner this looks to me as approach to get the XML template, I might use to correctly format the Netconf payload. In fact, I succeed to do so with the IETF interfaces YANG model:

pyang -t edit -f sample-xml-skeleton yang/standard/ietf/RFC/ietf-interfaces.yang --sample-xml-skeleton-defaults

After that I tried to get a “template” for IOS-XE ntp servers:

$ pyang -f sample-xml-skeleton yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ntp.yang --sample-xml-skeleton-defaults
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ntp.yang:5: error: module "cisco-semver" not found in search path
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ntp.yang:11: error: module "Cisco-IOS-XE-types" not found in search path
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ntp.yang:14: error: module "Cisco-IOS-XE-native" not found in search path
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ntp.yang:17: error: module "Cisco-IOS-XE-interface-common" not found in search path
sample-xml-skeleton plugin needs a valid module

As you can see, I got an error message.

I also tried running the command in the respective YANG Model folder or by adding the path parameter to the command. Both generated the (more or less) same warning messages:

cd yang/vendor/cisco/xe/1781/
pyang -f sample-xml-skeleton Cisco-IOS-XE-ntp.yang --sample-xml-skeleton-defaults
[output omitted]

==============================
pyang -t edit -f sample-xml-skeleton -p yang/vendor/cisco/xe/1781/ yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ntp.yang --sample-xml-skeleton-defaults
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:636): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:1620): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:1623): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:1635): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:1782): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:1785): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:1962): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:2420): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:3944): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:4031): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:4155): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:4449): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:5556): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:5559): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:5572): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:5751): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:5754): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:5941): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2592 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-interfaces.yang:6310): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-interfaces"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1615): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1790): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1793): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1796): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1799): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1802): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1805): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1808): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1811): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1814): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1817): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1820): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1823): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1826): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1829): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1832): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1835): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1838): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1876): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1879): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1882): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1885): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1888): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1891): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1894): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1897): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1900): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1903): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1906): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1909): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1912): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1915): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1918): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1921): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:1924): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:3232): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:3288): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2543 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ip.yang:3816): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ip"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2565 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ipv6.yang:503): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ipv6"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2565 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-ipv6.yang:527): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-ipv6"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2862 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-logging.yang:235): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-logging"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2862 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-logging.yang:244): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-logging"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2862 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-logging.yang:673): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-logging"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2862 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-logging.yang:728): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-logging"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2862 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-logging.yang:860): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-logging"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2862 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-logging.yang:922): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-logging"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2862 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-logging.yang:1120): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-logging"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2862 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-logging.yang:1135): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-logging"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2862 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-logging.yang:1168): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-logging"
yang/vendor/cisco/xe/1781/Cisco-IOS-XE-native.yang:2862 (at yang/vendor/cisco/xe/1781/Cisco-IOS-XE-logging.yang:1183): warning: node "Cisco-IOS-XE-native::native" is not found in module "Cisco-IOS-XE-logging"
<?xml version='1.0' encoding='UTF-8'?>
<data xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"/>

I am now wondering whether there might be an issue with the IOS-XE 17.8.1 YANG models and how to proceed. Any support is very much appreciated. Thank you, a lot, in advance for your support.

[miott]

The ntp model augments the Cisco-IOS-XE-native model so looking directly at the ntp model will give you nothing.  I suggest you look at https://developer.cisco.com/yangsuite.  Yangsuite will gather together all the model dependencies and give you a visual tree structure to look at.  You can also interact with devices using various protocols like NETCONF, RESTCONF, and gNMI.

[DrSchw0b · Accepted solution]

Thank you for pointing me into the right direction. I was able to get the required XML "template" with pyang using the following command:

pyang -f sample-xml-skeleton Cisco-IOS-XE-native.yang Cisco-IOS-XE-ntp.yang --sample-xml-skeleton-defaults --sample-xml-skeleton-path=/native/ntp

I learned that the file names of all required models must be passed to pyang for it to work. The "tree" output with a single model might work; however, this model might lack the surrounding element structure. For the NTP servers to be set, the "native" tags must surround the "ntp" element.

[Umesh Shetty]

@DrSchw0b where did you get the /native/ntp from as the path ?

[DrSchw0b]

Hello@Umesh Shetty,

unfortunately, I haven't had a chance to use YANG since those days. If I remember correctly, "/native/ntp" is the path within the YANG structure from which we wanted to get the XML skeleton. This path is used to "carve away" the unnecessary tree structure of the "entire" native model, to focus just on the NTP configuration. So we just get the XML structure of what is of interest for us. You could select any leaf in the tree by use of the path option. You can derive the path form the nodes within the YAML tree structure.

On another note, my problem was solved by passing not only the NTP YANG model to pyang, but also the model in which the NTP model is embedded: Cisco-IOS-XE-native.yang Cisco-IOS-XE-ntp.yang

[Umesh Shetty]

Thanks @DrSchw0b , I have a folder structure cloned from GIT Yang repo and my module depends on the ietf-native but also a couple others. Should I be listing all the dependent modules ?